反应详情

4-(3-Nitrophenyl)thiazol-2-amine (1.10 g, 5.0 mmol) was dissolved in dry pyridine (16 mL) and then 3,4-dimethoxybenzene-1-sulfonyl chloride (1.323 g, 5.59 mmol) was added. The reaction mixture was stirred at room temperature for 23 h and then the pyridine was flashed off in vacuo with toluene. The residue was slurried with EtOAc and water. Full solution was achieved and then ice cold 1M NaOH was added. After thorough shaking, the aqueous phase was separated and the organic phase was twice extracted with 1M NaOH and then with water until no yellow color was extracted. The aqueous extract was combined with the NaOH solution and the solution was made slightly acidic with 3M HCl. The product was extracted into EtOAc, then washed successively with H2O and saturated NaCl solution. After drying over Na2SO4, the solvent was removed in vacuo to give a gum which contained HOAc. This was flashed off with toluene. The foam remained slowly solidified and after drying in vacuo, weighed 1.632 g (77.4%) and was greater than 95% pure by TLC. This material was taken up in hot EtOAc, diluted with about one-half the volume of hexane while hot which induced crystallization. The first crop weighed 1.352 g and was pure by TLC, but had no distinct melting point. Yield of pure material (TLC) was 64.2%.

1. customAfter thorough shaking, the aqueous phase was separated
2. extractionthe organic phase was twice extracted with 1M NaOH
3. extractionwith water until no yellow color was extracted
4. extractionThe aqueous extract
5. extractionThe product was extracted into EtOAc
6. washwashed successively with H2O and saturated NaCl solution
7. dry with materialAfter drying over Na2SO4
8. customthe solvent was removed in vacuo
9. customto give a gum which
10. customafter drying in vacuo
11. additiondiluted with about one-half the volume of hexane while hot which
12. customcrystallization